Support single node upgrades to PostgreSQL 16

What does this MR do?

Support single node upgrades to PostgreSQL 16

Add support for upgrades from the bundled PostgreSQL 14 to PostgreSQL 16 of single node instances.

Upgrades must be triggered explicitly, auto upgrades are not enabled.

Closes #8337 (closed)

Changelog: changed

Related issues

Checklist

See Definition of done.

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Required

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Expected (please provide an explanation if not completing)

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